From: Alex Deucher <alexander.deucher@xxxxxxx> Mac laptops with multiple GPUs apparently use the gmux driver for backlight control. Don't register a radeon backlight interface. We may need to add other pci ids for other hybrid mac laptops. Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=65377 Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- drivers/gpu/drm/radeon/atombios_encoders.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c index 8406c82..4120d35 100644 --- a/drivers/gpu/drm/radeon/atombios_encoders.c +++ b/drivers/gpu/drm/radeon/atombios_encoders.c @@ -186,6 +186,13 @@ void radeon_atom_backlight_init(struct radeon_encoder *radeon_encoder, u8 backlight_level; char bl_name[16]; + /* Mac laptops with multiple GPUs use the gmux driver for backlight + * so don't register a backlight device + */ + if ((rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) && + (rdev->pdev->device == 0x6741)) + return; + if (!radeon_encoder->enc_priv) return; -- 1.7.7.5 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html